Metal cutting oil derived from oxidized petroleum oil



Patented Mar. 2? 1954 UNITED STATES PATENT OFFICE 2,673,183 METAL CUTTING OIL DERIVED FROM OXIDIZED Everett 0. Hughes,

PETROLEUM OIL Shaker Heights, and David Frazier, Bay Village, Ohio, assignors to The Standard Oil Company, Cleveland, Ohio, a corporation of Ohio No Drawing. Application August 16, 1949, Serial No. 110,674

13 Claims. (Cl. 252-34.7)

The present invention relates to a novel neutralized, oxidized oil suitable for use particularly as a cutting oil or as an additive to a cutting oil base stock, and to a process of preparing the same. i

It is known sive substitute for the lard oil normally included in a cutting oil blend but which may also be an and containthen neutralizing it with a strong base. Examples of such light Oils for oxidation are light solvent-extractranging from about 300 to about 600 SUS at 100 F, and an optical density of between 100 and 300.,

The oxidation may, e. air through the oil for taining the oil at an the order of 200 to 350 It is important that the oxidized oil obtained in this step have a saponification number between 20 and 80. The final oil will not be soluble in the cutting oil base if the oil so obtained is corrosive, and is parafiin cutting The oxidized strongly acidic, and therefore not compatible with ordinary oil bases.

The oxidized oil is then neutralized with a strong solid or liquid base selected from the mixture is heated to C. for approximately an hour.

When the neutralization is carried out with a liquid base, the required amount of liquid base is simply stirred into the oil. It is observed that the When the oxidized oil has been neutralized 3 with either a solid or liquid base, any water or alcohol contained therein, such as that used to dissolve the base, may be removed by any suitable method such as by air blowing the oil at an elevated temperature, until the water or alcohol content is less than about 0.1% by weight.

Elemental sulfur may be, and preferably is, added to the oxidized and neutralized oil so produced. This is best accomplished while maintaining the oil at an elevated temperature of the order of about 60 C. so that the sulfur may readily dissolve therein. The oil is then cooled to crystallize out any excess of undissolved sulfur. Alternatively, the oxidized and neutralized oil may be added either to a sulfurized cutting oil base or to an unsulfurized cutting oil base. In the latter event it is necessary to dissolve sulfur in the unsulfurized blend.

The oxidized and neutralized oil produced in accordance with the method of this invention, whether the oil is sulfurized ornot, is entirely compatible with and soluble in ordinary sulfurized and unsulfurized cutting oil stocks such as straw oils having viscosities ranging between about '75 and 150 SUS at 100 F. It has an A. S. T. M. neutralization number between +1.0 and -2.0, contains less than 0.1% water in oil, by A. S. T. M. and is soluble and stable at in a neutral paraffin oil having a viscosity of 100 SUS at 100 F.

With a given cutting oil stock, sulfurized before or after the blending thereof with oxidized oil, it has been found that concentrations of the oxidized oil of this invention in amounts ranging from about 8 to about by weight are optimum for reducing the wear, and therefore increasing the life of, a cutting tool. Concentrations as low as about 3% and as high as 100%, i. e., the sulfurized composition itself without any cutting oil base, to equal or to be superior to the best known sulfurized cutting oils available on the market.

One of the advantages of the present invention is that it provides an inexpensive, abundant and reliable source of cutting oil additive which, when blended with any known cutting oil base, imparts to it the desirable property of greatly prolonging the life of a cutting tool.

Another advantage of the invention is that it provides a simple and easily controlled method for producing a sulfurized oil that is not only superior when used in place of lard oil but may be used by itself as a cutting oil.

These and other advantages as well as the utility of the invention will become more apparent from the following examples.

Example 1 A light solvent-extracted oil having a viscosity of 115 SUS at100 to a saponification number of 58 and a neutralization number of 18. The oxidized oil was neutralized'by adding 1% by weight of water, which was stirred in well, and the subsequent addition have, however, been found r.

F. was oxidized with air of 2% by weight of lime, which was likewise stirred in well. The mixture was heated to 100 C. for one hour and then blown with air for an additional hour while maintained at 100 C. The neutralized oil was allowed to cool and settle.

The oxidized oil so neutralized was found to be compatible with paraffin oils and to form a clear solution when 20 parts thereof are mixed with 80 parts sulfurized straw parafiin oil having a viscosity of 100 SUS at 100 F. and containing 1% sulfur.

Example 2 A solvent-extracted oil similar to that treated in Example 1 was oxidized with air to a saponification number of 47 and a neutralization number of 15 and then neutralized in substantially the same manner with 3% by weight of lime. The neutralized oil thus obtained was blown with air as in Example 1 and was found to exhibit physical properties similar to produced in accordance with Example 1. parts of the neutralized oil were blended with parts of a sulfurized straw paraffin oil having a viscosity of SUS at 100 F. and containing 1.2% of sulfur.

Example 3 A light solvent-extracted oil similar to that treated in accordance with Example 1 was oxidized with air to a saponification number of 53 and a neutralizationvnumber of 13. A stoichiometric amount of potassium hydroxide inwater, as indicated by the neutralization number of the oxidized 'oil, was then stirred into the oil. so oxidized. This resulted at first in a milkysuspension which was resolved after a minute or two'and became perfectly clear. The oil thus neutralized was blown with air for hour and the oil was maintained atv a temperature-of 100 C.

The resultingoil wasxfound 'to be compatible with straw paraflin .oil. A blend of 1.6 parts neutralized oil and 84 partsstraw oil was saturated with sulfur by heating with excess sulfur. The excess sulfur crystallized out and was filtered off. The mixture contained 1.7% sulfur.

Example 4 A light solvent-extracted oil similar to" that treated in Example 1 was oxidized toua saponification number of 60 and a neutralizationnumber of 18. A stoichiometric excessof 60% potassium hydroxide in water was stirred into the oil; so oxidized. The reaction appeared to: be approximately the same as. described in Example 3 except that the neutralized oil became darker and more viscous, apparently due to the excess potassium hydroxide. This oil was blown with air and 0.75% by weight of elemental sulfur was-dissolved therein by saturating ,the oil with sulfur at 60- C. and then cooling to crystallize :outthe excess sulfur.

Example 5 v The method of Examplee was repeated with the exception that initial oil was oxidized to a neutralization number 17 and the oxidized oil was neutralized with a 30% solution-of'potassium hydroxide in methanol and 0.7% by weight of sulfur was dissolved in the neutralized oil."

The oil blends prepared in Examples 1 to -3, and the neutralized oils prepared in Examples-"4 and 5, alone and in various concentrations as additives to paraffin stravvoil having a viscosity of 100 SUS at 100 F, and sulfurized toa sulfur content of 1.7%, were field tested on an automatic drill milling machineto determine their effect upon tool life.

In each test; the work piece was regular Momax HS steel. a spiral of 22,

stock of Both flutes, having were milled simultaneously, then indexed to a second position where both margins were clearance milled. The mechanical'fa'ctors of the flute mill were: 0.218" depth on both sides, 1.625 per minutefeed, 176 surface feetperrmiriute speed, and ZO-toothedcutters.

The normal tool lifeexpectancy onthis machine, under the same conditions and with the use of one of the best cutting oils'on the market, made by dissolving 1% by weight of sulfur in 20% lard oil and 80% parafiin straw oil having a viscosity of 100 SUS at 100 F., is from 36 to 39 drills.

The results are listed in the table below:

Concentration, in percent by Weight of Cutter oxidized 011 Life in cutting oil composition ing a viscosity of 100 SUS at 100 F. and sulfurized to a sulfur content of 1.7%, without the addition of an oxidized and neutralized oil, resulted in a cutter life of only 27.4.

Another test, conducted with a 16% concentration of an oxidized and neutralized oil preresulted in a cutter life of 0.

These tests show that sulfurized cutting oil when the concentration of the oxidized oil in the base ranges between about 8% and 50%, and that neutralization with a solid base gives somewhat better results than neutralization with a liquid base.

The term optical density in the present disclosure represents the standard logarithmic ratio of intensity of an incident ray falling on a transto 5,500 Angstroms.

It is to be understood that innumerable variations and modifications will immediately become apparent to those skilled in the art upon reading the foregoing disclosure. The invention contemplates all such variations and modifications as come within the scope of the appended claims.

We claim:

0., an aromatic content below about 12%, and containing less than 0.2% total sulfur, to a said oil.

4. A neutralized, oxidized, solvent refined, light mineral oil substantially free of water and alcohol and containing dissolved elemental sulfur, said neutralized, oxidized oil having, before neutraliza- 5. A cutting 011 comprising a mineral oil base stock and at least about 3% by weight of a neutralized, oxidized, solvent refined, light mineral 6. A cutting oil comprising a sulfurized mineral oil base stock and at least about 3% by weight of a neutralized, oxidized, solvent refined, light mineral oil substantially saturated with dissolved sulfur, said neutralized, oxidized oil being substantially free from water and alcohol and having, before neutralization, a saponification number between about 20 and and having been neutralized with a base.

7. A cutting oil comprising a sulfurized mineral oil base stock and at least about 3% by Weight of a neutralized, oxidized, solvent refined, light minhaving, before neutralization, a saponification number between about 20 and 80 and having been neutralized with a base.

8. A cutting oil comprising a mineral oil base stock and at least about 3% by weight of a neuhaving an A. S. T. M. aniline point over 0., an aromatic content below about 12% and containing less than 0.2% total sulfur to a saponification number between about 20 and 80, neutralizing cutting oil composition before blending or in the blended composition.

10. The method defined in claim 9 wherein the elemental sulfurais" dissolved in the mineral outting oil base stock before blending said component with: the neutralized, oxidized oil.

11, The method defined in-claim 9 wherein the elemental sulfur is dissolved in the neutralized, 5

oxidized oil before blending saidcomponentwith the: mineral cutting soil base stock.

12; Themethod defined inelaim 9 wherein the elementalsulfur is dissolved in. both theneutralized, oxidized oil and the mineralcutting oil base stock ,beforethey are blended.

13. The method defined in claim9 wherein the elemental sulfur. is dissolved in the blend after blending of. the neutralized, oxidized oil componentwith a mineral cutting oil stock.

EVERETT C. HUGHES. DAVID. FRAZIER;

8 Reterenccs Cited inl-the file of this patent:- UNITED STATES PATENTS Number- Number Name Date. MacCoull June 24, 1930 Burwell June 14,, 1932 Mackenzie Apr. 18; 1933 Gallsworthy Jan. 8, 1935 Karns June 21, 1938 Parkhurst Jan. 3, 1939 Zimmer Nov. 26, 1949 Zimmer June 1'7, 1941 Morway Aug. 12, 1941 Bray Sept. 30, 1941 Ruedrick Jan. 16, 1945 Rogers Mar. 12, 1946 FOREIGN PATENTS.

Country- Date Great Britain Sept. 10, 1930 

5. A CUTTING OIL COMPRISING A MINERAL OIL BASE STOCK AND AT LEAST ABOUT 3% BY WEIGHT OF A NEUTRALIZED, OXIDIZED, SOLVENT REFINED, LIGHT MINERAL OIL THAT IS SUBSTANTIALLY FREE OF WATER AND ALCOHOL, AT LEAST ONE OF SAID COMPONENTS HAVING ELEMENTAL SULFUR DISSOLVED THEREIN AND SAID NEUTRALIZED, OXIDIZED OIL COMPONENT HAVING, BEFORE NEUTRALIZATION, A SAPONIFICATION NUMBER BETWEEN ABOUT 20 AND 80 AND HAVING BEEN NEUTRALIZED WITH A BASE. 